L25, Plyometrics

Question 1

What is plyometric training?

Answer 1

• Dynamic activities that enable a muscle to reach maximal force in a very short time
• Quick powerful movements using a pre-stretch or countermovement

(utilises the SSC)

Question 2

What is the goal of plyometric training?

Answer 2

• Decrease the amount of time between eccentric contraction and the initiation of concentric contraction
• Increase speed and force of contraction
• Controlled deceleration

(Run faster, jump higher)

Question 3

What two mechanisms does the stretch-shortening cycle make use of?

Answer 3

• Mechanical: Energy storage in the elastic component (tendon)
• Neurophysiological: Stimulation of the stretch reflex to facilitate maximal muscle recruitment over small amount of time

Question 4

What is the stretch reflex?

Answer 4

The body’s involuntary response to an external stimulus that stretches the muscles

(when muscle spindles are stimulated, the stretch reflex is stimulated)

Question 5

What are the three primary neural adaptations to plyometric training?

Answer 5

• Increased activation of fast-twitch motor units and higher firing rate
• Improved explosive force with minimal increase in muscle girth
• Golgi tendon inhibition= Higher threshold for muscle tension and activation, thus increasing power of muscle contraction and output

Question 6

Who should do plyometric training?

Answer 6

Sports that involve jumping, sprinting, change of direction or agility

Question 7

Why is intensity important in plyometric training?

Answer 7

If intensity is too high it will alter the neural training and may hinder progress

Question 8

True or false, high volume training sessions are no more effective than low volume sessions due to fatigue?

Answer 8

True

Question 9

What level of volume should beginners, intermediate, and advanced athletes perform each session?

Answer 9

1. 80-100 beginners
2. 100-120 intermediate
3. 120-140 advanced

Question 10

What frequency should plyometric training occur?

Answer 10

2-3 sessions per week, 2-3 days rest

Question 11

What order should plyometric training be performed?

Answer 11

Power, other core, and then assistance exercises

(complex multi joint exercises first and then accessory exercises last)

Question 12

Are there any program pre-requisites to plyometric training?

Answer 12

The general consensus is that if appropriately implemented, PT is safe for most individuals

Question 13

How do we assess the outcome of a plyometric program?

Answer 13

Reactive Strength Index (RSI)

(a measure of reactive jump capacity)